A shaft coupling of the tandem membrane type is utilized in the form of a fully metallic shaft coupling, the membranes consisting of sheet metal, while the inner and outer rings are connected by the membranes which compensate for alignment errors of the shaft axes and relative angular offsets thereof. A schematic overview of this type of shaft coupling and the characteristics of such couplings are given by K. Ehrenspiel and G. Henkel in VDI Berichte (VDI Reports), No. 299, 1977, page 161.
The present invention is concerned primarily with membrane couplings of the type described in the literature (Op. Cit., page 162) and referred to as double couplings with outwardly disposed intermediate membranes. In such systems, two machine elements, for example shafts, are coupled with compensation for relative axial, angular and radial displacement with the aid of an intermediate member coupling the individual axially spaced membranes in series or in succession.
A series connection of the membranes increases the permissible angular and axial offset in proportion to the number of membranes. This construction also has the advantage that the connection region of the so-called intermediate member is substantially free from forces since this region is generally free to move in the radial direction.
A problem with earlier shaft couplings of the type in which two or more individual membranes are coupled together by intermediate members in accordance with prior art principles, is that the overall length of the shaft couplings may be greater than desired. Problems with assembly, connection and disconnection of such shaft couplings have also arisen.